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The Three-Gorges Dam in China
The purpose of Sustainable Water Management is simply to manage our water resources while taking into account the needs of present and future users. According to this definition, I think The Three-Georges Dam in China can only partially be counted as "Sustainable" strategy. Here is an amazing video that introduced Three-Gorges Dam by discovery channel! http://dsc.discovery.com/videos/discovery-china-revealed-three-gorges-dam.html 1. The basic INFO. of The Three Georges Dam The Three Georges Dam is a hydroelectric dam that spans the ........its 2,335 metres long yay......angtze River by the town of Sandouping, located in the Yiling District of Yichang, in Hubei province, China. The Three Georges Dam is the world’s largest capacity hydroelectric power station with a total generating capacity of 18,200 MW. The dam body was completed in 2006. Except for a ship lift, the originally planned components of the project were completed on October 30, 2008, when the 26th turbine in the shore plant began commercial operation. Each turbine has a capacity of 700 MW. Six additional turbines in the underground power plant are not expected to become fully operational until 2012. Coupling the dam's thirty-two main turbines with two smaller generators (50 MW each) to power the plant itself, the total electric generating capacity of the dam will eventually reach 22,500 MW. As well as producing electricity, the dam increases the Yangtze River's shipping capacity, and reduces the potential for floods downstream by providing flood storage space. The Chinese government regards the project as a historic engineering, social and economic success,with the design of state-of-the-art large turbines, and a move toward limiting greenhouse gas emissions.However, the dam flooded archaeological and cultural sites and displaced some 1.3 million people, and is causing significant ecological changes, including an increased risk of landslides. The dam has been a controversial topic both in China and abroad. 2. How does the Dam work? ''thumb|link='' Power generation is managed by China Yangtze Power a listed subsidiary of China Three Georges Corporation (CTGPC) a Central Enterprise SOE administered by SASAC. The Three Gorges Dam is the world’s largest capacity hydroelectric power station with twenty-six 700 MW turbines and a total capacity of 18,200 MW. Eventually, it will have 32 generators: 30 main generators, each with a capacity of 700 MW, and two plant power generators, each with capacity of 50 MW, making a total capacity of 22,500 MW. Among those 32 generators, 14 are installed in the north side of the dam, 12 in the south side, and the remaining six in the underground power plant in the mountain south of the dam. The expected annual electricity generation will be over 100 TWh. The main generators weigh about 6,000 tonnes each and are designed to produce more than 700 MW of power. The designed head of the generator is 80.6 meters (264 ft). The flow rate varies between 600–950 cubic metres per second (21,000–34,000 cu ft/s) depending on the head available. The greater the head, the less water needed to reach full power. Three Gorges uses Francis turbines. Turbine diameter is 9.7/10.4 m (VGS design/Alstom's design) and rotation speed is 75 revolutions per minute. Rated power is 778 MVA, with a maximum of 840 MVA and a power factor of 0.9. The generator produces electrical power at 20 kV. The outer diameter of the generator stator is 21.4/20.9 m. The inner diameter is 18.5/18.8 m. The stator, the biggest of its kind, is 3.1/3 m in height. Bearing load is 5050/5500 tonnes. Average efficiency is over 94%, and reaches 96.5%. The generators are manufactured by two joint ventures. One of them includes Alstom, ABB Group, Kvaerner, and the Chinese company Haerbin Motor. The other includes Voith, General Electric, Siemens (abbreviated as VGS), and the Chinese company Oriental Motor. The technology transfer agreement was signed together with the contract. Most of the generators are water-cooled. Some newer ones are air-cooled, which are simpler in design and manufacture and are easier to maintain. The 14 north side generators are in operation. The first (No. 2) started on July 10, 2003. The north side became completely operational September 7, 2005 with the implementation of generator No. 9. Full power (9,800 MW) was only reached on October 18, 2006 after the water level reached 156 m. The 12 south side generators are also in operation. No. 22 began operation on June 11, 2007 and No. 15 started up on October 30, 2008. The sixth (No. 17) began operation on December 18, 2007, raising capacity to 14.1 GW, finally surpassing Itaipu (14.0 GW), to become the world's largest hydropower plant. The underground power plant and its six generators are expected to be completed by 2012. 3. Another Main Function of the Dam''' '' An important function of the dam is to control flooding, which is a major problem for the seasonal river of the Yangtze. Millions of people live downstream of the dam, with many large, important cities like Wuhan, Nanjing, and Shanghai situated adjacent to the river. Plenty of farm land and China's most important industrial area are built beside the river. The reservoir's flood storage capacity is 22 cubic kilometres (18,000,000 acre·ft). This capacity will reduce the frequency of major downstream flooding from once every ten years to once every 100 years. The dam is expected to minimize the effect of even a "super" flood. In 1954 the river flooded193,000 km2 (74,518 sq mi), killing 33,169 people and forcing 18,884,000 people to move. The flood covered Wuhan, a city of eight million people, for over three months, and the Jingguang Railway was out of service for more than 100 days. The 1954 flood carried 50 km3 of water. The dam could only divert the water above Chenglingji, leaving 30 to 40 km3 to be diverted. Also the dam could not protect the large tributaries such as the Xiangjiang,Zishui, Yuanshui, Lishui, Hanjiang, and Ganjiang. In 1998 a flood in the same area caused billions of dollars in damage; 2,039 km2 (787 sq mi) of farm land were flooded. The flood affected more than 2.3 million people, killing 1,526. In early August 2009, the largest flood in five years passed through the dam site. The dam limited the water flow to less than 40,000 cubic metres (52,000 cu yd) per second, raising the upstream water level from 145.13 metres on August 1, 2009, to 152.88 on August 8, 2009. 4.27 cubic kilometres of flood water were captured and the river flow was cut by as much as 15,000 cubic metres per second. The dam discharges its reservoir during the dry season between December and March every year. This increases the flow rate of the river downstream, and provides fresh water for agricultural and industrial usage. It also improves shipping conditions. The water level upstream drops from 175 m to 145 m, preparing for the rainy season. The water also powers the Gezhouba Dam downstream. Since the filling of the reservoir in 2003, the Three Gorges Dam has supplied an extra 11 cubic kilometres of fresh water to downstream cities and farms during the dry season. During the 2010 South China floods, in July, inflows at the Three Gorges Dam reached a peak of 70,000 m3/s (2,500,000 cu ft/s), exceeding the peak during the 1998 Yangtze River Floods. The dam's reservoir rose nearly 3 m (9.8 ft) in 24 hours and reduced the outflow to 40,000 m3/s (1,400,000 cu ft/s) in discharges downstream, effectively alleviating serious impacts on the middle and lower river. '''''4. The sustainable part I have to admit that the Three-Gorges dam solved the shortage of electricity in China. The Three Gorges Dam is the world’s largest capacity hydroelectric power station with twenty-six 700 MW turbines and a total capacity of 18,200 MW. Eventually, it will have 32 generators: 30 main generators, each with a capacity of 700 MW, and two plant power generators, each with capacity of 50 MW, making a total capacity of 22,500 MW.Among those 32 main generators, 14 are installed in the north side of the dam, 12 in the south side, and the remaining six in the underground power plant in the mountain south of the dam. The expected annual electricity generation will be over 100 TWh. The Three-Gorges Dam largely reduced the coal consumption in China and thus reduced the carbon dioxide emission. According to the National Development and Reform Commission of China, 366 grams of coal would produce 1 kWh of electricity during 2006. At full power, Three Gorges reduces coal consumption by 31 million tonnes per year, avoiding 100 million tonnes of greenhouse gas emissions, millions of tonnes of dust, one million tonnes of sulfur dioxide, 370,000 tonnes of nitric oxide, 10,000 tonnes of carbon monoxide, and a significant amount of mercury. Hydropower saves the energy needed to mine, wash, and transport the coal from northern China. From 2003 to 2007, power production equaled that of 84 million tonnes of standard coal, reducing carbon dioxide by 190 million tonnes, sulfur dioxide by 2.29 million tonnes, and nitrogen oxides by 980,000 tonnes. The dam increased the Yangtze's barge capacity sixfold, reducing carbon dioxide emission by 630,000 tonnes. From 2004 to 2007 a total of 198 million tonnes of goods passed through the ship locks. Compared to using trucking, barges reduced carbon dioxide emission by ten million tonnes and lowered costs 25%. The dam catalyzed improved upstream wastewater treatment around the large city of Chongqing and its suburban areas. According to the Ministry of Environmental Protection, as of April 2007 more than 50 new plants could treat 1.84 million tonnes per day, 65% of the total need. About 32 landfills were added, which could handle 7,664.5 tonnes of solid waste every day. 5. The Unsustainable Partthumb|link= Two hazards are uniquely identified with the dam. One is that sedimentation projections are not agreed upon, and the other is that the dam sits on a seismic fault. At current levels, 80% of the land in the area is experiencing erosion, depositing about 40 million tons of sediment into the Yangtze annually. The absence of silt downstream has two effects: 1. Some hydrologists expect downstream riverbanks to become more vulnerable to flooding. 2. The city of Shanghai, more than 1,000 miles (1,609 km) away, rests on a massive sedimentary plain. The "arriving silt—so long as it does arrive—strengthens the bed on which Shanghai is built... the less the tonnage of arriving sediment the more vulnerable is this biggest of Chinese cities to inundation..."Benthic sediment buildup causes biological damage and reduces aquatic biodiversity. Earthquake-induced peak ground acceleration coupled with the immense weight of the reservoir water might be able breach the upstream face of the dam. Erosion in the reservoir, induced by rising water, causes frequent major landslides that have led to noticeable disturbance in the reservoir surface, including two incidents in May 2009 when 50,000 and 20,000 cubic metres (65,000 and 26,000 cu yd) of material plunged into the flooded Wuxia Gorge of the Wu River. Also, in the first four months of 2010, there were 97 significant landslides. Another unsustainable thing about this dam is that it ruined the gorgeous view of the Three-Gorges and significantly changed the ecology there. The 600 kilometers (373 mi) long reservoir flooded some 1,300 archaeological sites and altered the appearance of the Three Gorges as the water level rose over 600 feet (180 m). Cultural and historical relics are being moved to higher ground as they are discovered, but the flooding inevitably covered undiscovered relics. Some sites could not be moved because of their location, size, or design. For example, the hanging coffins site high in the Shen Nong Gorge is part of the cliffs. 6. Limitations of Three-Gorges Dam The United States Department of Defense reported that in Taiwan, “proponents of strikes against the mainland apparently hope that merely presenting credible threats to China’s urban population or high-value targets, such as the Three Gorges Dam, will deter Chinese military coercion.”The notion that the Taiwanese military would seek to destroy the dam provoked an angry response from the People's Republic of China media. People's Liberation Army General Liu Yuan was quoted in the China Youth Daily saying that the People’s Republic of China would be "seriously on guard against threats from Taiwan independence terrorists." Days after the first filling of the reservoir, around 80 hairline cracks were observed in the dam's structure.The submerged spillway gates of the dam pose a risk of cavitation, similar to what severely damaged the spillways of the Glen Canyon Dam in the floods of 1983.The project claimed that 163,000 concrete units of the dam all passed quality testing and that deformation was within design limits. An experts group gave the project overall a good quality rating. Another limitation of the dam is that the government has to relocate the residents. As of June 2008, China relocated 1.24 million residents, ending with Gaoyang in Hubei Province), about 1.5% of the province's 60.3 million and Chongqing City's 31.44 million population. About 140,000 residents were relocated to other provinces.Relocation was completed on July 22, 2008. Chongqing City will encourage an additional four million people to move away from the dam to the Chongqing metropolitan area by the year 2020.Allegedly, funds for relocating 13,000 farmers around Gaoyang disappeared after being sent to the local government, leaving residents without compensation. 7. Future of Three-Gorges Dam In order to maximize the utility of the Three Gorges Dam and cut down on sedimentation from the Jinsha River, upstream of the Yangtze River before reaching Yibin, China plans to build a series of dams downstream of Jinsha, including Wudongte Dam, Baihetan Dam, Xiluodu Dam, and Xiangliaba Dam. The total capacity of those four dams is 38,500 MW, almost double the capacity of the Three Gorges. Xiluodu and Xiangjiaba are under construction, while Baihetan is preparing for construction and Wudongde is seeking government approval. Another eight dams are in the midstream of the Jinsha and eight more upstream of it. Here are some interesting links about Three-Gorges Dam http://www.cnn.com/SPECIALS/1999/china.50/asian.superpower/three.gorges/ http://www.pbs.org/itvs/greatwall/dam.html http://www.time.com/time/world/article/0,8599,1671000,00.html Category:The Three-Gorges Dam Category:sustainable water management Category:The sustainable water management in China